This invention relates to methods and means of providing a controlled gas environment against a workpiece surface, and in particular for providing a controlled gas atmosphere against a selected area of a semiconductor wafer surface of controlled temperature, pressure and composition to which the wafer can be introduced, processed and removed while in an ambient environment, without immersing the entire wafer in the gas environment and encountering the attendant difficulties of opening and closing static gas seals.
The invention has particular application to some of the gas (dry) processes in the fabrication of integrated circuits including processes of deposition, impurity implantation and other gaseous chemical processes and laser induced gaseous processes such as ablative photodecomposition (APD). A specific embodiment of the invention described herein includes gas flow controls to maintain a flowing gas seal against the surface of the wafer while maintaining the desired gaseous conditions within the seal at the selected processed area of the wafer, for radiation induced processes like deposition, impurity implantation, ablation and others and to carry away any particles or gaseous by products produced by the process and used process gas.